The Underhill stalwart has made close to 400 appearances for The Bees during two stints with the north London club and last season stepped up to assistant Hendon following his appointment as manager.
The pair guided Barnet to League Two safety and Harrison is now looking to secure a new deal with the club, allowing his relationship with Hendon - who recently penned a two-year contract - to prosper further.
"Ian is keen for me to assist him next season," he said. "We live pretty close together and pretty much travel in together all the time. It works pretty well and we discuss things pretty much every day.
"I've known Ian since I was 11, we played for Essex schools together and we're good friends as well as good work colleagues. I'm not scared to tell him how I feel or if I disagree. He wears his heart on his sleeve and I'm more laid back so it works well.
"I'm out of contract this summer and whether that means staying on as a player and backing up again or finding a new number two and me stepping aside and being solely an assistant, I don't know. I'm confident of staying, I've been there 10 years and I know the place better than anyone."